In the interest of building an experience-diverse workforce employers need entry level, mid level, and experienced developers with skills in their core stack, which in many cases is Java or .NET.
My theory is that technology trends are leading the entry level developers to learn Python, Ruby, and JavaScript rather than .NET or Java, thereby reducing the supply and putting these candidates in high demand.
So, they could hire another senior person at 2.5x the pay instead of 3-4 junior devs. The problem is a lot of younger managers don't understand the different in ouput can vary a lot from developer to developer. And on top of that quality output can be far more maintainable.
All they care about is # of jira/tfs tickets that are open, and the number of features, and how many warm bodies based on their averages they need. The smoothest project I ever worked on was staffed by all senior people, with relatively diverse and overlapping skills. That wouldn't be possible with 3x the developers if 2/3 of them were junior to mid level.
My theory is that technology trends are leading the entry level developers to learn Python, Ruby, and JavaScript rather than .NET or Java, thereby reducing the supply and putting these candidates in high demand.